Main.java Source code

Introduction

Here is the source code for Main.java

Source

import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

import javax.swing.ComboBoxModel;
import javax.swing.DefaultComboBoxModel;
import javax.swing.JComboBox;
import javax.swing.JFrame;
import javax.swing.JPanel;

public class Main extends JPanel implements ActionListener {
    JComboBox<String> combo1 = new JComboBox<>(new String[] { "Course 1", "Course 2", "Course 3" });
    JComboBox<String> combo2 = new JComboBox<>();
    ComboBoxModel<String>[] models = new ComboBoxModel[3];

    public Main() {
        models[0] = new DefaultComboBoxModel<>(new String[] { "A1", "A2" });
        models[1] = new DefaultComboBoxModel<>(new String[] { "B1", "B2", "B3", "B4" });
        models[2] = new DefaultComboBoxModel<>(new String[] { "C1", "C2" });

        combo2.setModel(models[0]);
        this.add(combo1);
        this.add(combo2);
        combo1.addActionListener(this);
    }

    @Override
    public void actionPerformed(ActionEvent e) {
        int i = combo1.getSelectedIndex();
        combo2.setModel(models[i]);
    }

    public static void main(String[] args) {
        JFrame f = new JFrame();
        f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        f.add(new Main());
        f.pack();
        f.setLocationRelativeTo(null);
        f.setVisible(true);
    }
}